var addAction = function() {
	var result = +document.getElementById("firstOperand").value + +document.getElementById("secondOperand").value;
	document.getElementById("result").innerHTML = result; 
		
};

var subAction = function() {
	var result = +document.getElementById("firstOperand").value - +document.getElementById("secondOperand").value;
	document.getElementById("result").innerHTML = result; 
};


$(document).ready(
	function() {
		$("#addButton").click(addAction);
		$("#subButton").click(subAction);
	}
);


function checkIsNumber(elem) {
	if ( isNaN(elem.value) ) {
		alert("Введите число!");
		return;
	};
	
};